Field of the Invention
RFID applications in industry concerning high temperature and demanding chemical applications usually require high-cost tags with an expensive but heat-resistant encapsulation. Most of the known industrially manufactured tags for harsh conditions are very expensive printed circuit boards, and they are encapsulated, being thus extremely expensive and rigid.
One special application in the field of the high temperature RFID tags is a tire tag. The tire tag should resist the harsh tire vulcanizing process which involves high temperatures and pressures. The existing tire tags are quite expensive and they comprise heat resistant encapsulations because without special structures the RFID transponder would break down. The tire tags may be embedded in the tire which is a disadvantage because an embedded tag can cause unexpected failure of the tire.
Publication U.S. Pat. No. 6,255,949 discloses in FIGS. 5 and 6 a high temperature RFID tag which comprises a flexible circuit board substrate, an IC circuit and an integrated circuit device, i.e. a chip. The integrated circuit device is bonded to the substrate by conventional means. On the top surface of the substrate there is a thermally resistant, substantially flexible silicone encapsulant. On the bottom surface of the substrate there is a high temperature adhesive.